feat: tsdoc for the definitions

MusicKitAPI.d.ts

@@ -1,4 +1,12 @@
 export interface MusicKitAPI {
+    /**
+     * This is the primary mean of accessing the Apple Music API.
+     * @see https://js-cdn.music.apple.com/musickit/v3/docs/index.html?path=/docs/reference-javascript-api--page
+     * @param path - The Apple Music API path to use
+     * @param params - The parameters to substitute in the path (params use Mustache syntax)
+     * @param options - Extra options to pass directly to the underlying fetch call.
+     * @returns The data in an object. The type varies across paths.
+     */
     'music': (
         path: string,
         params: {